Update tensorboard nightly dependency to 2.2.x

Now that TensorBoard 2.1.0 has been released, our nightlies have moved
up to 2.2.x alphas.

PiperOrigin-RevId: 286091571
Change-Id: I33a2b679bc91ec9e46423a5eea298a01a5df7a10
diff --git a/tensorflow/tools/pip_package/setup.py b/tensorflow/tools/pip_package/setup.py
index f33f7bd..90205a5 100644
--- a/tensorflow/tools/pip_package/setup.py
+++ b/tensorflow/tools/pip_package/setup.py
@@ -92,7 +92,7 @@
 if 'tf_nightly' in project_name:
   for i, pkg in enumerate(REQUIRED_PACKAGES):
     if 'tensorboard' in pkg:
-      REQUIRED_PACKAGES[i] = 'tb-nightly >= 2.1.0a0, < 2.2.0a0'
+      REQUIRED_PACKAGES[i] = 'tb-nightly >= 2.2.0a0, < 2.3.0a0'
     elif 'tensorflow_estimator' in pkg and '2.0' in project_name:
       REQUIRED_PACKAGES[i] = 'tensorflow-estimator-2.0-preview'
     elif 'tensorflow_estimator' in pkg: